Month: November 2014

In spite of the up coming Thanksgiving holiday, and all the people who are out of town, 15 people showed up at Johns shop, and they weren’t disappointed. John had several hands on demonstrations for people to try. One of the most popular was the shaving horse.

John demonstrating the shaving horse.

Only Denny and John tried Johns lathe which was set up for out board turning after the hard maple blank started chipping.

Drum sander in action.

Routing using a templet on top of wood.

The results

John’s drum sander was cool to watch. John demonstrated his pin router using a templet for his clock gears. I didn’t get any pictures of the flex tool carving station, or the sanding station.

Watch your fingers Mike!

But just as important was the chance to visit with everyone.

John’s wife, Fay, served up some delicious home made goodies on the lanai. Boy can she bake! It was worth the price of admission just for the food.

For this meeting, Denny presented his own special tips and techniques for producing segmented turnings. As expected, segmented turnings can be quite complex, so Denny broke down his thinking into separate sections for this meeting.
He began with recommending a favorite book of his, “Segmented Wood Turning,” by William Smith.
Notably, he pointed out some charts and angles in the back of the book. Angles can be confusing, so remember there are 360° in a full circle. Tonight’s project has 24 segments, so some simple math has that 360° divided by 24 segments yields 15° each. What is not apparent at first glance is that the 15° for each segment gets divided in half, so each side of each segment gets 7.5°. Keeping that in mind for now, Denny goes on to point out that expansion and contraction in the bottom of any bowl can be a problem, since the wood grain in the bottom generally runs in one direction while the grain of the side segments runs around the bowl with a differing angle for each segment.
Next, Denny brought out his laptop and showed us how his favorite turning software, “Wood Turner’s Studio,” which Denny says is simple and fast to use. The software was originally developed by Craft Supplies USA, on the web at: http://www.woodturnerscatalog.com/b/39/Craft-Supplies-USA.
Interestingly, the software is no longer available there, but other sources exist. A screen shot is shown below.
A web search shows a site called “ software.informer” has the software available on this site: http://woodturner-studio.software.informer.com/1.0/ (sorry, neither I nor the club can endorse any software or online download, but if you have success with this, you can let the members know.)
As Denny was demonstrating the drag and shift nature of this software, he informed us of another detail, called padding. Since the software computes segment sizes, and their glue up can be critical, it is to the advantage of the turner to allow some “fudge factor” or extra amount of wood to be turned off in the bowl building process. Speaking of a fudge factor is a good segue to Denny’s next topic of jigs to control the cutting and building up process.
To illustrate, if on a closed segmented bowl with 24 segments, each with 7.5° cuts at each end, suppose that each cut was off by only 1/10° each. As the error multiplies around each layer of the bowl, 24 segments would sum to 2.4°. That means that either the bowl would have gaps in it, or that the segments would be too long. Predictably, Denny next showed off some of the jigs used to make his cuts.
For an open segmented bowl, small angle differences become invisible in the gaps as long as the gaps are uniform. Here, he is satisfied with his Inca miter gauge accurate to 1/10°. He groups several layers of the bowl to allow ripping with identical widths. Then he cuts the angles on the table saw with the miter gauge. The length of the 24 segment pieces is dialed in by small adjustments to his stop. He cut, measured, and adjusted the miter stop with an automotive feeler gauge. When satisfied, he makes 24 pieces, flipping the stock over after each cut. He allows a little extra thickness that is trimmed off with a jig mounted on his lathe at a later step. He lightly sands the pieces by hand to knock off the fuzz.
Next Denny demonstrated how he gets each layer to be the exact final thickness required in the layer he is working on. For this, he worked on a layer previously glued up on the work piece that had sufficient time for the glue to dry. Here he mounted a hand held router in a wooden strap mounted in turn to a
cross slide vice. The router had a straight trimmer bit, and the entire assembly was mounted on the lathe bed. The lathe was turned in the reverse direction to the router bit’s direction and a low rpm was selected. This jig quickly removed the extra stock down to the intended 1/8” thickness.
Denny’s next jig is a Plexiglas round set on the outboard side of the lathe. The Plexiglas has degree markings all around, and Denny used a vertical alignment piece that indicates then the lathe was turned to the desired angle, at which point he clamped the alignment piece in place and glued on the first of the next layers of segments. He likes Gorilla Glue in a one ounce dispenser bottle. One can find product details here: http://www.gorillatough.com/gorilla-wood-glue.
Denny says he can disregard the recommended clamp time of 15 to 20 minutes, and reduces that down to less than a minute for each piece. He says that once the glue wets the wood on both pieces, that it has high initial tack and generally stays puts. He showed us that if one piece comes loose, it can be easily refastened. As he glued up these segments, Denny demonstrated yet another jig, this one to set the segment’s penetration into the interior of the piece, and to hold the intended angle. After the glue dries, the same router jig is used to set the layer thickness according to plan. The balance of the layer glue up reads like shampoo directions, lather rinse repeat. After the layers are complete, and sometimes in between sections, the inside and outside of the work can be turned. That was left for another day, as the session ran out of time.

Denny uses this software to design the bowl. It calculates the size and exact location of each segment.

Ready to flush the last layer.

Denny designed this jig to align the segments, but it required removing the bowl from the lathe for each layer. He moved on to another idea.

Another alignment jig that mounts to the bed of the lathe, this one works best.

This jig fits on the lathe bed to align each segment as it is glued to the layer.

Denny’s home made rig for flushing the end of each layer as it is glued to the bowl.

General Meeting October 8, 2014
Set Your Teeth on Handsaws by Larry Simmons

Larry opened with some common definitions useful for the balance of his presentation.
PITCH: Teeth per inch.

Rule of thumb for saw lengths and pitch ( teeth per inch)

RAKE Angle: Larry presented a chart showing the different rake angles based on whether a saw is a rip or cross cut saw, and also dependent on the saw’s use in either hard or soft wood. Zero degree rake angle means the front of the saw’s teeth are presented at 90 degrees to the surface of the wood, for instance.

Rake for different types of saws

FLEAM: The angle of the file when sharpening the teeth. Fleem refers to filing the back of one tooth and front of the other. Usually zero degrees for a rip filed blade, and ranging from 15 to 25 degrees on crosscut saws.
HANG: The angular relationship of the saw’s handle to the cutting edge. The handle needs some downward angle in order to transfer some power to the cutting edge. Aside from hang, many people purchase a saw based on how well it fits the individual’s hand. (If it feels good, it probably is, for you.)
RUN: This is the hand saw equivalent of runout on a machine tool. To demonstrate, draw a line to be cut and begin a cut by hand. After well underway, look away and continue sawing. If the saw does not follow the line, that is the run.
PPI: Points per inch.

Larry’s interest started from the acquisition of a hand powered cast iron miter saw that is almost as heavy as a powered miter saw. The blade was caked with dirt and dull, so Larry decided to learn how to sharpen hand saws. Larry often omits a power saw on his jobs, instead just powering the saw by hand.

Miller Falls cast iron miter box and saw

Larry showed some various saw types. Ripping saws have teeth with a flat bottom (looking from left to right on the saw)and some set. Crosscut saws have teeth filed on an angle, and also have a set.

Several different cordless saws

More saws

Disston hand saws have a distinctive emblem on one of the sex bolts or saw bolts. This brand is highly regarded and formerly they had 75% of the American market. More of the history of Disston hand saws is available on the internet.www.disstonianinstitute.com
Saws are measured by the blade length, and saws were sold by the inch. Commonly, rip saws were a little longer due to the angle the worker used, a lesser angle allowed a longer blade to be used without hitting the floor when using a saw bench.

Best angle

Larry’s rip saw has 6 teeth per inch. Rip saws are ineffective when used in a crosscut manner.
Panel saws are so called because they are shorter than others and often were fitted into the lid (or panel) of a workers tool box. Aside from that, they mimic other saws.
Triangular files are used to sharpen saws. Larry presented a chart showing the size files used depending on the pitch of the saw. Try to avoid using more than ½ of the file buried in the teeth so that when one edge of the file wears out, it can be rotated 60 degrees and further used.

All the files you don’t really need.

Jointing saws does not refer to the current medical marijuana initiative, but rather to setting all the file teeth in the same plane. Larry showed a flat mill bastard file set into a short board, which not only holds the file, but also holds the file at 90 degrees to the blade. A few strokes will usually make all the teeth the same height.

Block of wood with a file in a slot, to joint the saw teeth square. The small slot is to hold a card scraper when sharpening.

5 steps to sharpen a really bad saw.

To joint the saw, Larry fastened the saw in a saw vice he purchased.

Saw vise

He also showed us a board with a kerf cut in it that can be made as long as needed. Just take a board of sufficient length and cut a saw kerf in it. Now, slide the saw in the kerf lengthways, and that board will hold the saw when clamped in a vise. The shiny spots at the top of the blade prove the height of the teeth. Teeth with larger flat spots means that the files needs to be pushed more into the tooth with the smaller flat spots. To add fleam, Larry uses blocks of wood with saw kerfs cut at the desired angles to help guide the file during sharpening. He no longer believes that most saws need fleam, stating that Paul Sellars taught him that, and he tried it and feels it works just fine.

Guides to help align the file to the correct fleam

Larry feels most saws have too much set, and cut too wide of a kerf. These saws are even difficult to withdraw from a cut on the back stroke. The saw set tool has two pistons, one to grip the saw and one to bend the tooth. There is a number adjustment on the saw set, with 4 corresponding to four teeth per inch. Make this adjustment when starting and the set is introduced when the handle is activated.

Saw set

After setting the teeth, joint the teeth again, but very lightly. Now sharpen again, perhaps only one stroke will remove the flat spot.
Dovetail saws are usually filled with a rip cut. Larry said Youtube has hours of videos showing how to sharpen hand saws. Search for Brit01425 on Youtube.